A variety of endoscopic biopsy forceps have been developed to allow samples of tissue to be taken during endoscopic procedures. Normally, a forceps is inserted together with an endoscope deep into a body cavity being examined, with the forceps adapted to cut and remove body tissue desired for examination. The forceps conventionally used in such procedures have utilized complex arrangements of linkage assemblies and/or camming devices for articulating the jaws of the forceps. As such instruments are of small size, such complexity results in complex machining and manufacturing procedures which greatly increase the cost of such instruments. Thus, present biopsy devices are generally very expensive and, the jaw actuating mechanisms are complex. Additionally, in such prior art devices, a rigid outer housing is normally provided for proper pivoting of the small jaws of the apparatus. Such an outer housing is used to hold the forceps together and must be subsequently removed to allow for a pivot point by means of a pin or screw around which the jaws of the forceps can open or close.
In the prior art, the combination of jaws, linkages, and an outer housing results in an instrument having a significant length thereof which is rigid. This rigidity associated with the instrument increases the potential for damage of the endoscope through which the device is passed to obtain a tissue sample. Endoscopic biopsy procedures require the repeated insertion and removal of the device through a narrow channel in the endoscope in order to obtain a tissue sample. The number of insertions and removals is determined by the number of tissue samples the operator desires to obtain, and each insertion or removal of the device can cause potential damage to the narrow channel of the endoscope or to the biopsy instrument itself.
Further, as many current biopsy devices are intended for multiple use, the possible damage to the endoscope or biopsy device itself is increased with currently-known apparatus. In conventional biopsy forceps, the intended multiple use of the instruments requires extensive cleaning and sterilizing procedures to be performed to comply with medical standards and use of such instruments. In order to be used a multiple number of times, a biopsy instrument must be sterilized by immersing a contaminated instrument in a suitable chemical sterilizing solution, or subjecting the apparatus to sterilization in an autoclave. In either instance, the sterilization and cleaning procedures will often decrease the performance or useful life span of such instruments, due to the complexity of its manufacture. Further, some devices which are intended only for a single use still incorporate complex linkage and/or camming devices for proper movement of the biopsy jaws, which greatly inhibits their use as the costs associated with such instruments are normally still very high.
Other deficiencies of prior art endoscopic biopsy forceps are found in activation of the biopsy jaw for opening and closing of the jaws. Other problems are noted in the jaws will many times crush tissue which may affect examination of the tissue, or require a larger amount of tissue to be removed for examination.